hi

ive been plagued by rot, losing some lilies to it, (all lilies are in pots). ok some of it was my fault in not ensuring there was decent drainage (my bad) , but here in the uk it does rain a lot!

so ive bought some copper sulphate crystals to add to the compost. i was wondering if anyone else has done this and what rate do you apply it?

i was thinking of adding the crystals direct, as opposed to making a solution in water and watering the pots.

If the directions say make a solution, I can't imagine any scenario where applying as a granule would be wise. The dosage would be completely impossible to predict, and you would end up treating parts of the soil at 50-500 times the recommended rate. Whether it would actually produce any long term advantage, disadvantage or damage, I couldn't say for sure. But you're playing with fire, in my opinion.

Copper prevents and stops roots from growing, I do not think this is a good idea at all. Try increasing the coarse matter in the potting mix, bigger bark or more pumice.

The rot can be due to too much moisture and also hotter temperatures. Lily bulbs don't do well when the temps are high and it can be more difficult to keep their "feet" cool in pots. Trying to compensate for either of these with chemicals will not work well. From my experience err on the side of too much drainage - as suggested add more grit or mulched wood. Peat moss in the mix breaks down over the season and your drainage will decrease. Many of the potting mixes are only good for one season and if I am potting anything for more than one season I mix 1/3 with wood chips/mulch to give structure and provide drainage.

If heat is an issue you can put the lily pot inside of a bigger pot, preferably a white or other reflective color. That will insulate the bulbs from the evil sun!

Regarding composts, I do not know if you are aware or not, Rob - I suspect you might be - but H.W Hyde uses a bracken compost by 'Dalefoot Composts' to grow their show plants in, but I assume they grow in a greenhouse and only one year so would not know how this work long term.

This isn't a specific lily potting mix but if you scroll down a bit in the PDF below you can see what Ian Young uses for his bulbs. I bet it would be very suitable for lilies as well and it certainly is a mix made for your climate. I can't imagine too much water being a problem in such a free draining mix.

http://www.srgc.org.uk/logs/lo...